Supercharger



4 Sheets-Sheet l S. OLD BE R G SUPER CHARGER Oct. 6, 1953 Filed Aug. 5, 1949 INVENTOR. SIDNEY OLDBERG yBY A ATTORNEYS Oct. 6, 1953 s, OLDBERG 2,654,530

SUPERCHARGER Filed Aug. 5, 1949 4 Sheets-Sheet 2 8283 ee /B\ 56 x4 los 92 f 54 es 92 ao 9o L M -f-f.

'54 JNVENToR.

SIDN EY OLDBERG BY f E@ +6 MW 7" ATTORNEYS Oct. 6, 1953 s. OLDBERG 2,654,530

SUPERCHARGER Filed Aug. 5, 1949 4 Sheets-Shea?. 5

INVENTOR. SIDNEY OLDBERG l |44 BY f PlE E ATTOR N EYS' Oct. 6, 1953 Filed Aug. 5, 1949 S. OLDBERG SUPERCHARGER 4 Sheets-Sheet 4 SIDNEY OLDBERG ATToRNEs clearance control in the form Patented Oct. 6, 1953 UNITED 2,654,530 SUPERCHARGER Sidney Oldberg, Birmingham,

Eaton Manufacturing Company,

Mich., assignor to Cleveland,

Ohio, a corporation of Ohio Application August 5, 1949, Serial No. 108,750

I 4 Claims.

This invention relates to rotary air impelling devices and more particularly to air impelling devices for use as superchargers for internal combustion engines.

Broadly the invention comprehends the provision of an internal combustion engine supercharger utilizing mating helical rotors and wherein novel structural details are incorporated relative to the disposition of inlet and outlet portions for desirable air flow through the rotors, provision for effective end clearance control of the rotors, provision for the effective lubrication of the bearings. of the supercharger, ley-pass means for shunting the outlet of the supercharger to the inlet thereof and other innovations of structure permitting of the installation of the supercharger to conventional internal combustion engines With little difficulty and occupying a minimum of space.

An object of the invention is the provision of an air impelling device of economical and compact construction, and light of weight.

Another object of the invention is the provision of a supercharger for internal combustion engines that is high in adiabatic and volumetric eiilciency throughY the improved overall construction thereof relative to rotor form, air iiow path provided from inlet to discharge thereof, end clearance control of rotors and proper lubrication of the meshing and bearing elements thereof, Vall incorporated in a structure of minimum size for a predetermined required capacity.

A further object of the invention is the provision of a supercharger for internal combustion engines having a combustion engine carburetor throttle valve and by-pass Valvefor the supercharger arranged at the inlet thereto permitting of simultaneous engine throttle control and bypassing air delivered to the engine intake manifold back to the supercharger inlet so as to reduce the work of the supercharger to aminimum undei` engine throttled conditions, the employment of the combination valve providing for a considerable saving in -height in the installation of the supercharger upon theengine.

A yet further object of the invention is the provision of a supercharger having keffective end Y of a novel spring loaded thrust bearing assembly for the air impeller lrotors thereof providing for increased low speed efficiency. v

p A still further object ofthe invention is the provision of a supercharger of the displacement type having a combination of endwise andl sideporty ing utilized in cooperation with mating helical ro- I Cil relation between tors wherebyA abrupt changes in the direction of air flow can be avoided, thus Vresulting in increased adiabatic and volumetric efficiency at high speed operating conditions. This form of porting is additionally helpful in reducing the overall size of the supercharger for installation purposes to internal combustion engines.

A still further object of the invention is the provision of a supercharger that is operable with a minimum of noise through the proper disposition of the inlet and outlet porting to one another ancia set of helical rotors employed permitting of substantially free air ilow therethrough and the mounting of the drive and driven gears aixed to the respective rotors upon taperedportions of shafts permitting phasing the gears relative to one another and xed Within permissible limits of gear backlash.

Other and further important objects and advantages of this invention will be apparent from the following description taken in connection with the drawings forming a part of the specification and in which:

Fig. l is a horizontal cross-sectional View of a supercharger, constituting the basis of thevinvention taken substantially along lines I-l of Fig.

along lines 4 4 of Fig, 3;

l Fig. 5,is a fragmentarybottom plan yview of the supercharger taken substantially along lines 5 5 of Fig. 3 showing theroutlet port thereof;

Fig-6 isa vertical cross-sectional View ofthe supercharger taken vsubstantially along lines 6-,8 of Fig. 4 .illustrating the pumping chamber and `the inlet and outlet ports thereof; Y. y f.

Fig. 7 is an enlarged fragmentary cross-sectional view illustrating the lubrication system for the supercharger;` and Fig. 8 is anenlarged fragmentary view-of'a thrust washer drive means assembly incorporated in the supercharger o f Fig. 1

The presently `devised superchargeroffthe displacement back-iiow compression type is arrived at providing just such a supercharger having high adiabatic and volumetric veiciencies Aatall ranges poration of tubular y `boreprovided in Yeach of the rotor shafts extend`V of speed so designed as to be light of weight and compact as to overall dimensions particularly with regard to the height thereof for installation purposes. This supercharger is of the general Roots blower type and constitutes a continuation in part of my co-pending application S. N. 763,633 filed July 25, 1947, now Patent No. 2,530,173.

The present structure in addition to preferably incorporating the construction of my aforementioned application especially with regard to the specific helical interengaging rotors provided includes improvement of structure relative to sev eral inter-related parts thereof. The basic improvements made are those directed to optimum air ow in view of compactness of size desired through the proper disposition of the inlet and outlet ports thereof to one another, end clearance control means in the form of a spring loaded thrust bearing assembly, an effective lubrication system affording ample lubrication for all relativelyV movablev and engageable members, effective mounting of the drive and driven gears for the rotors of the supercharger permitting of proper Vdesired phase relation therebetween and the provision of a combination by-pass and throttling valve.V

An optimum air flowisachieved forthe compact design here presented by locating the porting in relative endwise and side porting relative vto one another, such as to approximately follow a path of ow void of abrupt changes in the direction of flow. This disposition of ports is appro.- priate considering the twist angle of the helical rotors employed in that it reduces turbulence and cyclic losses thereby improving materially the adiabatic and volumetric efficiency of the supercharger.

By providing an effective and clearance control of the rotors through the use of a suitably designed spring loaded thrust bearing arrangement a very substantial increase in'low speed efficiency is obtainable. The use of a spring loaded thrust bearing assembly provides for the accomplishment with simplicity of the self-alignment as well as uniform bearing loading for the support of: the 'rotors in end clearance control. The presently constructed spring loaded thrust bearing comprises the application of a'xed load by means of a flexible member which acts through all the thrust surfaces and which forces a surface rigidly fixed to the rotating shaft of y each rotorl to bear against a stationary `thrust bearing surface. Y

The lubrication systemV for the supercharger derives Yits source ofpressure lubricant from the engine to which the supercharger is adapted and provides through an ingenious arrangementv of lubricant flow channels for the effectiveflubrica- Ation of all the bearings and relatively rotatable surfaces Vof the mechanism incorporated inthe 'supercharger aside from the pumping surfaces of the rotors, the pumping chamber of which is sealed from communication. with the lubricating system. The desirable and effective distribution of lubricant is accomplished through the incorsleeve members in an axial ing axially therethrough permitting of the ow oflubricant internally as well as externally ofthe tubular sleeves for distribution to a plurality of locations requiring lubrication. In this manner allbearing and moving partsv are assured of ampleflubricationfor allV operatingjspeeds of the supercharger.

' The drive and driven gears, one associated Y most importance since it determines the amount of backlash or clearance between the rotors, which in turn has an appreciable effect upon the superchargers efficiency.

Referring to the drawings for more specic details of the invention, Ill represents generally a supercharger or air blower of the displacement type generally adaptable to the supercharging of f air forA subsequent delivery to the combustion chambers of internal combustion engines or the like comprising a blower housing or case Il consisting of three major elements, a blower shroud I.2',a rear cover plate I4 and a front gear housing I6, said blower shroud I2 and cover plate I4 pro'- viding a pair of intercommunicating chambers land 28. therebetween. Whereas the cover plate Ulis suitably secured upon the shroud I2' at its open end 22 the housing i6 is suitably secured upon the oppposite axial end of the shroud l2 and forms therebetween with an end wall portionv 24 thereof a gear chamber 26.

"A pair of identical three lobed rotors 28 and 3D are arranged for air propelling engagement with one another respectively in chambers I8 and 20 'and are each cast upon or otherwise suitably secured to appropriate shafts 32 and 34 respectively therefor. The shaft 32 is journaled at one end plate I4, intermediate its length upon a combina- 'tion stationary thrust and radial bearing. 40 flxedly secured upon' end wall portion 24 of shroud l2 and near its other end v2in hub sec-. tion 44, of housing IB. The extremity of end 42 of shaft 32. extends beyond the hub section 44 of housing I6 and is adapted to have a sheave or pulley 46 splined thereto, said pulley in turn being adapted to be driven by a belt, not shown, driven from an engine Withwhich the supercharger is to be associated.

The shaft 32 in being Ydriven from its associated engine is designated'the driving or input shaft of thel supercharger whereas shaft 34 is designated the driven shaft, said shaft`34 being mounted for rotation similarly to' shaft 32v in that it is supported at one end 48 in a sleeve bushing 58 mounted in cover plate I4V and near its other end 52 upon a combination stationary thrust and radial bearing 54. The bushing 50 and bearing Starei'dentical respectively to the bushing 38 and bearing 40 associated with shaft 32, the purpose of bearings 48 and 54 of which will hereinafter further appear.

The shafts 32 and 34 are each provided., with tapered portions 56 and 58Y respectively located 1n close proximity to the journaledV portions thereof on the respective bearings i8 and'` 54.

fixedly secure the gears upon the shafts resisting movement relative thereto and the nuts are held from rotative motion relative to their shafts by clinch washer 66 having axial ears 68 and 13 extending in a direction opposite to one another When in assembled form for appropriate receipt in slots of the shafts and nut. The shafts 32 and 34 are each provided with a slot i2 for receipt of ear 68v of washer 66 and the nuts have a plurality of axial grooves or slots 14' circumferentially spaced on the exterial surface of the nut for receipt of the ear 'I0 of the washer in the slot juxtaposed the ear when the nut is screwed up tight, said ears l0 being bent axially therein only after the nut is tightened.

The gears Sii and 32 in their mounted relation to one another upon shafts 32 and 34 are engageable for meshing rotation in gear chamber as induced for motion for power delivered to shaft 32 through pulley 45.

A front thrust washer 'i3 is provided for assembly intermediate the gears 63 and 62 and their respective associated bearings 43 and 54 having one face 'I8 thereof in planar axial contacting relation upon the front face 8u of the bearings 40 -1 and 54 with which associated. The washers 16 are each reduced in axial width at their inner diameter 8| so as to afford radial control thereof by limited contact with the external surface of their associated shaft and have a shoulder porftion 82 for axial receipt and impingement of a coil spring 83 disposed between the respective gear and washer for loading the thrust surface 18 of the Washer upon the thrust receiving surface of the bearings and for rotatively driving the thrust washer.

'I'he bearings 43 and 54 each have arranged in thrust bearing relation on faces 84 thereof axially oppositely disposed from faces 83 a rear thrust washer 85 which bears axially thereon. thrust washers 83 are ring shaped having a pair of oppositely disposed planar surfaces 88 and 93 respectively, surfaces 88 of which engage the bearing faces 84, and an internal circular surface radius chamfer at one axial end in annular L line contacting relation thereof 32 the chamfered edge 92 of which are adapted tohbear. onk a straight chamfered shoulder 94, one of which is formed on each of theshafts 32 and 34. The shafts 32 and 34 each have portions 96 thereof radially inwardly located of the internal diameter of the thrust washer with annular clearance therebetween and a drive spring assembly 38 is interposed in the annular clearance between the shafts 32 and 34 and their respective washers 85. Whereas the bearings 43 and 54 establish the plane of rotation of the respective washers 33 associated therewith the cooperating chamfers 92 and 94 of the respective washers and shafts x the radial and axial positions of the washers while the spring assembly 98 provides a driving connection between the shafts. and washers. Through the provision of the linecontacting relation of the washer chamfer 92 on chamfered shoulder 94 of the shaft with which it is associated a proper radial and axial position ofthe washer is assured without the necessity of maintaining fnite tolerance of the associate elements.

The washer spring drive means 38 comprises a ring member |00 having a flat portion |32 fitted appropriately on a complementary external surface of portion ofthe shafts 32 and 34 for the stationary retention thereof and an elliptical shaped spring Y member |92 `xed at diametrically opposite points by welding or; the

The L like to ring member |00 at its narrow width and with its maximum width points in resilient engaging relation upon the inner wall of the thrust washer for frictional engagement therewith. This arrangement provides an effective washer driving means for the proper maintenance of alignment radially andr axially and balance in the torsional rotation thereof.

The face of each thrust axial spring pressed washer has sealing engagement with seal assemblies |03 xedly arranged in annular openings |04 formed in the end wall portion 24 of shroud |2 in surrounding relation to the shafts 32 and 34 respectively.

The hub section of housing IB has arranged thereon in encompasing relation to end 42 of shaft 32 a sealing member |33, said sealing member effective to inhibt the leakage of lubricant delivered to the gear chamber 26.

The seal assemblies |32 in cooperation with thrust washers prevent the leakage of lubricantA from the gear chamber into the pumping chambers of the supercharger and simultaneously effect a sealing of the supercharger for the leakage of air therefrom.

The shafts 32 and 34 at their ends adjacent the sleeve bushings 38 and 3G respectively are each engaged by fluid seals |38 mounted in annular openings ili formed in the end cover plate I4, said seals inhibiting the leakage of lubricant into the pumping chambers of the supercharger.

The shafts 32 and 34 are each provided with axial bores ii'and ||4krespectively extending therethrough a predetermined distance the open end Ht of each bore communicating by way of passageway ||'1 in cover plate` I4 with a lubricant supply, not shown. The bore |2 in shaft 32 communicates with groups of axially spaced radial holes H8, |252, |22 and |24 for the appropriate distribution of lubricant respectively to the sleeve bushing 38, thrust washer B6, bearings 43 and 54 and hub journal 42. The bearings 43 and 54 are each slotted in their oppositely disposed faces to permit of the flow of lubricant therebetween with the thrust vwashers bearing thereon. Each group of holes ||8, |20, |22 and |24 comprises a plurality of circumferentially spaced holes extending from the bore ||2 -radially outwardly to the external surface l thereof for the conveyance of fluid lubricant therethrough.

The bore i4 in shaft 34 has similar communication to bore i|2 in shaft 32 with groups of axially spaced holes |26, |28 and |33 providing for the conveyance of fluid lubricant to the respective sleeve bushing 50, washer 86 and bearing 54 associated therewith. The group of holes |23,|28 and i3@ each comprises a plurality of circumferentially spaced'radial extending holes.

A-s a positive means of insuring the delivery of lubricant to the many parts of the supercharger requiring lubrication each of thebores ||2 and 4 have inserted therein a tubular sleeve |32 having 'enlarged portions |34 andr I 36 at their opposite ends adapted to fit the bore with a tight fit providing when in assembly an annular channel |33 with the wall of the bores for the passage lof lubricant therein.

rThev sleeves E32 serve to provide internally thereof a direct passageway for the supply of lubricant therethrough from passageway ||1 to holes |22 and |24 in the case of shaft 32 and to holes |33 in the case of shaft 34.

The lubricant delivered to passageway I |'|.in

vaddition to passing into sleeves |32 is fed'around Z sleeve bushings 381 and. 50 and thence through holes IIB, channel |38 and holes |28 to washer 8B `associated with shaft 32 and through holes |26, channel |38 and holes, |2 associated with shaft 34.

Through the press t of the sleeves |32 inthe respective bores II2 and II4 the high pressure oil is positively separated from the low pressure oil wherein channels |38 constitute low pressure oil passages and the passages internally of the sleeves constitute high pressure oil passages such that the thrust surfaces of washers 86 receive overow oil from bearings 40 and 54y respectively and overow oil from the sleeve bearings 38 and 58 respectively with the overflow therefrom delivered into the gear housing.

The porting for the supercharger includes an inletl port M in cover plate |4 communicating intermediate the chambers I8 and 28 by way of angular channel passage I42disposed for the delivery of fluid into the chambers between the rotors-,28 and 38 and an outlet port |44 of trapezoidal. shape arranged in the bottom of blower shroud I2 communicating with the chambers I8 and 28 intermediate thereof, the purpose of which will hereinafter appear.

The-ports |46 and |44 are disposed at right angles to one another for the purpose of providing porting which lies approximately in a plane parallel to the direction of air flow of the supercharger due to the twist of the rotors impelling the air in such a directional path, and in this way substantially prevents turbulence losses, cyclic losses and minimize leakage losses. By controlling these losses to a minmum increased adiabatic and volumetric eiiiciencies under high speed operating conditions are otbained.

For the purpose of eliminating work of the supercharger under throttling conditions of an engine to which it is applied, a by-pass housing I 46 is mounted upon the cover plate I4 of the supercharger having a ported connection |48 communicating with the inlet porting |40 of the supercharger, a ported connection |58 and a ported connection |52. The ported connection |58 is arranged for communication with an engine manifold |54 by Way of port |55 therein, and the. manifold in turn has communication by way of port |58 therein with the outlet port |44 thereby., establishing a path of communication between supercharger chambers I8 and 20 through port |44, port 158manifold |54, port |56, port |58 through lay-pass housing |46 and with ports |48 and |52 respectively with the inlet. |40 of the supercharger and with. a carburetor |6=8arranged in communication with port |52 mounted upon the Icy-pass housing |46.

The communication of portll for air delivery through the by-pass housing to the respective ports |48 and |59 is controlled by, a dual purpose throttle and by-pass valve I2 adaptedfor pivotal adjustment at the junction ofY ports |48, |50 and |52v therein as shown by full lines full capacity delivery to the supercharger is had'and .when in dotted line positionv the supercharger does appreciably no work in that under this condition itis only necessary torforce the by-pass air Vthrough the by-pass duct- The dotted line position of valve |62 represents throttled position for the engine to which thersupercharger is applied wherein the manifold pressure is to be atmospheric or less and wherein it is necessary to provide idle `iet tEd .permitting of the throttled condition of operation ofthe engine.

The positioning of the porting |40 and |44 of the supercharger with respect to blower shroud I2 thereof permits of the installation assembly of the by-pass housing T connection between the carburetor and manifold in communication with the supercharger, thereby effecting a saving in height ininstallation, elimination of extra piping and an extra Valve over conventional forms of supercharger installations.

Although the drawings and specifications. dene a supercharger of specificdesign and applications, it is conceivable that various departures in structure can be made therefrom without materially alteringv the basic concepts, thereof. and accordingly the invention is limited only to the extent of the appended claims drawn in terms of the basicideas disclosed` What I claim is:

1. A rotary blower comprising a blowerv housing having axially opposite end walls, a pair of intercommunicating chambers and inlet and. discharge ports arranged intermediate the chambers, one of said end Walls having a pair of spaced openings therethrough, a pair of stationary bearings secured to the said wall of the housing having the spaced openings therethrough, each` of said bearings being inV concentric relation to one of the spaced openings, a pair of rotors, one in each chamber, mounted for interengaging rotative relation in a zone between the chambers, a pair of shafts, one for each rotor, journalle'clY at one end in one end wall of the blower housing and each including portions extending axially beyond the other end Wall of the housing, journalled in one of the stationary bearings, a pair of intermeshing gears, one afhxed to the portion of each shaft extending beyond said one end wall of the housing, and a spring loaded thrust bearing assembly for each rotor arranged on each shaft adjacent the said one end of the housing having the portions of the shafts extending therebeyond comprising a Washer bearing axially upon one axial extremity of its associated bearing. a spring axially interposed between the washer and its associated gear and a second Washer disposed on the opposite side of its associated bearing', from the first washer, axially interposed ybetween a portion of its associated shaft and stationary bearing in axial bearing relation thereto.

2. A. rotary blower comprising a blower housing having axially opposite end walls, a pair of intercommunicating chambers and inlet and' discharge. ports arranged intermediate the chambers, one ofV said endl walls having a pair of spaced openings therethrough, a pair of stationary bearings secured to the said Wall ofthe housing having the spaced openings therethrough, each of said bearings being in concentric relation to one of the spaced openings, a pair of rotors, one in each chamber, mounted for interengaging rotative relation ina zone between lthe chambers, a pair1 of shafts, one foreach rotor, journalledv at one end in one end wall of the blower housing and each including portions extending axially beyond the other end wall ofthe housing, journalled in one of the stationary bearings, each including a reduced portion on one extremity, said reduced portion providing an annular. shoulder adjacent the end wall ofthe housing having the spaced openings therethrough, a pair of intermeshing gears, one axed to the portion of each shaft extending beyond said one end wall of thehousing, and' a spring loaded thrust bearing assembly for each rotor arranged onA each shaft adjacent the said one end of the housing having the portions of the shafts extending therebe'yond comprising a Washer bearing axially upon one axial extremity o-f its associated bearing, a spring axially interposed between the washer and its associated gear and a second washer disposed on the opposite side of its associated bearing, from the first washer, axially interposed between the shoulder on its associated shaft and stationary bearing in axial bearing relation thereto.

3. A blower according to claim 2 wherein the second washer is resiliently mounted on its associated shaft and rotative therewith.

4. A blower according to claim 2 wherein a spring member is inserted radially intermediate the second washer and its associated shaft and has a portion xedly secured to the second washer and another portion xedly secured to the associated shaft.

SLDNEY OLDBERG- References Cited in the iile of this patent UNITED STATES PATENTS Number Number Name Date Blazer Oct. 11, 1898 Ellis June 16, 1925 Hallett Sept. 17, 1935 Horton Feb. 14, 1939 Lysholm June 3, 1941 Whiteld June 23, 1942 Lysholm Sept. 26, 1944 Paget July 26, 1949 Paget July 26, 1949 Lysholm Aug. 22, 1950 FOREIGN PATENTS Country Date Great Britain Dec. 8, 1932 Great Britain Apr. 16, 1937 

